A car bomb exploded on Monday outside the ruling AKP headquarters in the eastern Turkish city of Van, wounding at least 50 people including two police officers, the local governor's office said.

Turkish officials have blamed the attack on the outlawed Kurdish PKK, which is listed as a terrorist group by Ankara and much of the international community.

The attack took place near a police checkpoint outside the AKP offices in the heart of the bustling city, the local governor's office said.

"Forty-six civilians and two police officers were injured after a bomb-laden car... was blown up by members of the separatist terror organisation," it added, using a term to describe Kurdish militants.

Nobody has yet claimed responsibility for the bombing, which comes on the first day of the Muslim holiday of Eid al-Adha. But Besir Atalay, an AKP politician from Van, also pointed to the PKK, which is waging a bloody campaign against the Turkish state.

"The terrorist organisation has targeted our party building and the AKP's presence in the past. This is one of their attacks," he said on the private NTV television.

Witnesses said the force of the blast shattered the windows in the surrounding vicinity and the AKP's provincial offices sustained severe damage.

Several ambulances rushed to the scene and television images showed water cannon being used to put out a fire caused by the explosion.

'Mayors cannot back terror'

Van, a city with a mixed Kurdish and Turkish population on the shores of the lake of the same name, has generally been spared the worst attacks, such as those seen in the nearby city of Diyarbakir.

The city is a popular tourist destination, particularly with Iranians who arrive from across the border in huge numbers to enjoy shopping and the relaxed atmosphere.

The blast came a day after the government announced the removal of 28 mayors, mainly over alleged links to the PKK, in a move strongly denounced by pro-Kurdish parties.

President Recep Tayyip Erdogan defended the suspension of the mayors, saying it was a long-overdue. "You, as mayors and municipal councils, cannot stand up and support terrorist organisations," he told reporters after prayers outside an Istanbul mosque, shortly before the attack. "You do not have such authority."

The government has stepped up its military campaign to eradicate PKK militants in the restive southeast. The PKK has launched attacks almost daily since the rupture of a fragile ceasefire last year.

Tens of thousands of people have been killed since the PKK first took up arms in 1984, with the aim of carving out an independent state for Turkey's Kurdish minority.

Turkey has also launched an operation inside Syria to remove Islamic State (IS) militants as well as Syrian Kurdish militia from its frontier.